1. Field of the Invention
The present invention relates to an information processing system, an information processing apparatus and an information processing method.
2. Description of the Related Art
For example, Japanese Laid-Open Patent Application No. 2008-071233 (Patent Document No. 1) discusses a technology that is for the purpose of preventing a third party from obtaining information. According to this technology, common information is created using a portable terminal and the created information is transmitted to an authentication apparatus and a user terminal. The user terminal generates authentication information from the received common information and transmits the generated authentication information to the authentication apparatus. The authentication apparatus also creates authentication information from the received common information and confirms whether the created authentication information is coincident with the authentication information received form the user terminal. When they are coincident, the authentication apparatus further confirms whether the common information received from the user terminal is coincident with the common information stored in the authentication apparatus. When they are coincident, the authentication apparatus determines that the user terminal is a valid one.
However, in this technology, when the common information is inadvertently disclosed, confidential information may be obtained by a third party.